Recommendation 3.1: All agencies with responsibility for homeland security should work together to establish stronger and more meaningful working ties between the intelligence, S&T, and public health communities.

Identification of Biological Agents in the Environment

At the present time, efforts to identify biological agents in air, soil, and water samples have had only limited success. Ideally, one would hope to be able to collect air samples, for example, and identify a pathogen in those samples in near real time, allowing the population to be warned of the pathogen’s presence. However, existing technologies for rapid and reliable detection (collection and identification) of bioagents have not been widely evaluated or well validated in real-world settings. Much greater attention must therefore be given to the transition between basic laboratory research and field application.

Traditional laboratory approaches include microbial cultivation, immunological (e.g., antibody-based) assays, and nucleic acid detection schemes, especially amplification methods such as the polymerase chain reaction (PCR). The last two approaches seek molecular evidence of agent components, such as characteristic immunological markers and genome sequences. A fourth broad approach relies upon the response of a surrogate host—such as cultivated cells from humans, animals, or plants.

Each of the four approaches has its advantages and disadvantages. It is important to note, however, that even though cultivation is slow, limited in scope (by ignorance of appropriate growth conditions in the test tube and in human tissues for many pathogens), and the least technologically sophisticated approach, it provides the most ready assessment of complex microbial phenotypes (behaviors), such as drug resistance. It also is the most widely used approach in laboratories throughout the world, especially in developing nations, and hence is currently the most common identification method for international surveillance.

A number of challenges must be addressed in order to develop and implement effective methods of environmental identification. An improved understanding of natural background is needed, regarding both the agent (including genetic, antigenic, geographical, and temporal variations) and the setting (including related agents and inhibitors). Additionally, standards must be established by which sampling and detection methods can be rigorously evaluated, validated, and standardized (see Recommendation 3.16 and surrounding discussions). Centralized repositories of diverse, high-affinity binding and detection reagents (e.g., antibodies, peptides, oligonucleotides) should be established, as well as repositories of genomic material and control samples. There are dozens of ways to identify bioterrorism agents that are sensitive and accurate. However, agreement on how a few well-developed platforms are implemented would allow the data to be broadly understood and make the limitations of the test used apparent to all.



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